Terminal extension fitting



May 29, 1962 F. G. FABIAN, JR., ETAL 3,036,601

TERMINAL EXTENSION FITTING Filed Oct. 31, 1958 3 Sheets-Sheet 1 May 29, 1962 F. G. FABIAN, JR., ETAL 3,036,601

' TERMINAL EXTENSION FITTING Filed Oct. 3l, 1958 3 Sheets-Sheet 2 May 29, 1962 F. G. FABIAN, JR., ETAL 3,036,601

TERMINAL EXTENSION FITTING Filed Oct. 31, 1958 3 Sheets-Sheet 3 greg.

Fatent @fire 3,636,661 Patented May 29, i962 3,036,601 TERMINAL EXTENSIGN FITTING Francis G. Fabian, Jr., and Robert N. Paterson, Bradford, Pa., assignors to Dresser industries, Inc., Dallas, Tex., a corporation of Delaware Filed Unt. 3i, 195g, Ser. No. 770,989 8 Claims. (Cl. 13S- 89) This invention relates to pipe connection devices and is more panticularly concerned with a fitting adapted for use in extending existing pipe lines, such as the lines of a gas distributing system.

In municipal gas distributing systems, it is necessary to provide extensions on existing lines from time to time either to accommodate the gas requirements of a newly built structure or to provide a new extension for an additional pipe line network to supply `a newly-developed area or an existing area into which the gas supply is to be newly extended.

When it is desired to connect an extension of this type to an existing gas line it has heretofore been necessary to shut down service over at least part of the existing line and reduce gas pressure before opening 'the line to eiiect the desired connection of the extension line. ln the case of small diameter lines, such an extension may sometimes be made without complete service interruption by permitting the gas to escape freely during the time the new extension is being incorporated. This practice, however, has many obvious disadvantages of a serious nature. Firstly, it is inherently dangerous owing to the escape of large volumes of gas and it requires highly skilled and reliable labor because of the speed with which the work must be accomplished to hold Ithe amount of gas escaping within some limits. However, this loperation necessarily lowers the pressure in the line even under the most `favorable conditions. Consequently, even if this operation does not cause service to be totally suspended, the efficiency of the service is greatly reduced and the danger of serious accident is ever present.

It is an object of this invention to provide a terminal pipe extension tting which is adapted to be applied to terminals of `an existing pipe system to permit rapid and simple connection with newly added extensions to the pipe netawork without necessitating the shutting down of service or reducing pressure in the existing system and while substantially avoiding the escape of gas from the line during the coupling operation.

lt is another object of the invention to provide la terminal extension `fitting of the character indicated which insures complete and effective sealing of the pipe terminal until it is desired to connect an extension yet which is readily accessible when required and permits the coupling of an extension with minimum effort and without the need for skilled labor.

It is a further object of the invention to provide a terminal extension fitting which lends itself to rapid and simple introduction of an extension line without special tools and without the necessity of threaded interconnection of the extension line into the existing line.

In accordance with the invention, the terminal extension fitting comprises a body portion having an axial bore and adapted to be connected at one end, as by welding, to the terminal end of the pipe line which is to be reserved for future extension. The other end of the body portion is constructed to receive an internal sleeve carrying a removable barrier which is automatically displaced upon introduction of the extension pipe, a removable closure for the tit-ting end to provide positive sealing of the end until the extension is to be connected, resilient sealing means such as a gasket to cooperate with the closure and with Ithe sleeve to seal these members against gas leakage, and means acting upon the resilient means to maintain sealing pressure at all times, both before and after incorporation of the extension line.

It is a feature of the invention that the structure of the terminal exten-sion fitting is such that an extension pipe may `be connected into it in duid-tight relationship without `the need of any additional sealing means and Without the need for threaded engagement.

It is another feature of the invention that the terminal extension fitting may be utilized to provide an extension to the terminal pipe with which it is associated merely by removing the closure and introducing the extension pipe into the open end of the itting, followed by tightening of the means applying sealing pressure to the resilient sealing element or gasket.

Other objects and features of the invention will be readily apparent from the following detailed description of illustrative embodiments taken with reference to the accompanying drawings wherein,

FIG. 1 is la diagrammatic view of a typical gas main network having terminal portions reserved for future extensions in connection with which the terminal extension fitting of the invention is adapted to be used;

FIG. 2 is a longitudinal sectional view of a terminal extension fitting embodying features of the present invention and illustrating one manner of interconnection with an existing terminal pipe;

FIG. 2a is a similar view of a modified form of the terminal extension fitting shown in FIG. 2;

FIG. 3 is `a perspective view, partly broken away in section, of the fitting shown in FIG. 2;

FIG. 4 is a View similar to that of FIG. 2 showing the relative relationship of parts upon partial introduction of an extension pipe into the fitting;

FIG. 5 is an elevational view of one manner of aligning the extension pipe and the fitting to begin the interconnection of the pipe into the fitting;

FIG. 6 is a view similar to that of FIG. 5 but showing a later step in the connection operation;

FIG. 7 is an elevational View showing the completed installation;

FIG. 8 is an elevational view similar to FIG. 5 showing rthe manner of handling the extension pipe if longitudinal movement of the pipe is not feasible;

FIG. 9 is similar to FIG. 8 `but shows a further step in the interconnection of the extension pipe ofl FIG. 8 with the terminal extension fitting;

FIG. l() is also similar to FIG. 8 showing .a still further step in the coupling operation; and

FIG. ll is an elevational view of the completed installation.

Referring to the drawings, `and more particularly to FIGS. 2 4, the :terminal extension tting l5 illustrated by way of example, to show a typical embodiment of the invention, has a main body 20 which is open at both ends and has a first end 22 which is adapted for interconnection with an existing terminal pipe indicated at 24, as by welding, the end 22 suitably having substantially the same internal and external diameter as the terminal pipe. The second end 25 of the body 2t) has an enlarged diameter and is internally threaded, as indicated `at 26, and is formed with a shoulder Z8 and a tapered mouth 30 defining a pipe receiving aperture and a gasket recess. Exteriorly, the end 25 is formed with threads 35 spaced axially inwardly from the end edge of the end 25 and leaving a cylindrical surface 36 of a diameter less than that of the threads 3S.

Cooperating with the end Z5 of body Ztl is a sleeve i0 which is externally threaded as shown at 42 for threaded engagement with the threads 26 and which has a flange portion 44 adapted to abut against the shoulder 23 when the sleeve is fully inserted into the body Ztl. The sleeve 40 has an axial bore 46 dimensioned to receive the extension pipe 4S with a free fit but without excessive clearance, the sleeve bore being advantageously formed to receive an extension pipe of the same diameter as the terminal pipe 24 which, as previously indicated, corresponds to the diameter of the end 22 of the body 2?. The axially inner end of the sleeve 40 is formed with a cylindrical surface 50 which is adapted to receive, with a slip-tit, the flange 52 of the barrier 54 which is adapted to form a displaceable closure for the fitting end and will be more fully described below.

Cooperating with the surfaces of the end 25 of body and with the axially outer end of the sleeve 40, is a gasket 60 of substantially right triangular cross-section having an inner end or toe 62 adapted to engage the axially-outer end of sleeve et) and the tapered surface of the mouth 3@ of the end 25. As shown in FIG. 2, the sleeve 40 advantageously has a tapered throat 64 to accommodate the toe 62 of the gasket 66, the slope of the throat 64 suitably corresponding to that of the mouth 38.

The gasket 6l? is formed from rubber or rubber cornposition, this term being used generically to include natural and synthetic rubbers and other elastomeric cornpounds, or compositions having like properties and characteristic. The material is relatively firm and solid but sufficiently resilient and elastic to flow under pressure to conform to the surfaces between which it is confined. Since the fitting 2@ is particularly adapted for use in connection with gas-distributing installations, the gasket 60 is advantageously formed from a rubber composition which is relatively resistant to attack by hydrocarbon gases and oils. Examples of such resistant rubbery compositions which are suitable for use are neoprene (polychoroprene) and butadiene acrylonitrile copolymers, such as those known commercially by the trade designations Buna-N or GR-A. The invention is, however, not limited to these specific materials, and when special resistance to gases is not required, any rubbery composition having the above-specified characteristics may be ernployed.

Cooperating with the end of body 2G is a follower 70 which is adapted to apply sealing pressure to the gasket 6l?. The follower 7l? is internally threaded at 72 for threaded engagement with the threads and has a pipe aperture 74 corresponding in diameter substantially to that of the axial bore 46 of sleeve 40'. In order to confine and protect the gasket 60 and to prevent frictional resistance by the gasket when the follower 70 is rotated in tightening or loosening it with respect to the body 2t), there is suitably provided a follower cup 76. In the embodiment shown in FIG. 2 wherein the parts are shown in free relationship before the follower 70 has been tightened upon the body 20, the follower cup 76 takes the form of an annular member conveniently stamped or otherwise formed from a metal sheet to define a body portion 78 formed with an aperture 79 sufficiently large to receive the extension pipe 48 and a peripheral flange 8) which is dimensioned to be received on the cylindrical surface 36 of the body 20.

To provide a fully pressure-resistant closure for the fitting and to prevent the entrance of dirt or other contaminants, the pipe 'aperture 74 is closed by a closure unit 81 which has a cylindrical body portion 82 and an end web 84 which extends beyond the body portion 82 to define a peripheral flange 86 having a diameter greater than the diameter of pipe aperture 74 and advantageously substantially equal to the internal diameter of the end 22 of body 2t). As will be seen in FIG, 2, the flange 86 bears against the axially-outer wall of the gasket 60 and is held in place by the follower 7l). The external diameter of the body portion 82 corresponds substantially to the external diameter of theextension pipe 48 which the terminal extension fitting l5 is adapted to receive and the body portion 82 is thus adapted to be received in the sleeve 4@ with a free fit.

As previously mentioned, the sleeve 40 carries a displaceable barrier S4 which is engaged with the sleeve 40 by means of a flange 52 which has at 52' an axially-extending `tab suitably about Ms long with a circumferential width of about l which is secured, as by soldering or spot welding, to the adjacent surface of the sleeve 40. Interiorly, the barrier 54 has a rib 88 of substantially right-triangular cross-section which is disposed on the same diameter line containing the tab 52 with the point of greatest axial distance of the rib from the barrier 54 being displaced circumferentially from the tab. A flexible seal material indicated at 52", such as Thiokol rubber, is used to seal the flange 52 with the sleeve 40. The barrier 54 and the rib 88 are suitably formed from a thin, e.g. .015 inch thick, sheet of metal, such as stainless steel, so that the barrier 54 will be bendable and readily displaced when the extension pipe 48 is brought to bear against it during interconnection of the extension pipe with the terminal extension fitting of the invention, as will be described below. Suitably the barrier S4 is provided with a pin-hole aperture 89 to permit slight leakage of gas into the chamber enclosed by the closure unit 8l and the barrier 54 in order to equalize pressures on both sides of the `barrier 54. As will be seen in FIG. 3, when the follower '70 is tightened upon the body Ztl, pressure is applied to the gasket 68, which transmits sealing pressure to the sleeve itl and the closure unit 81 to effectively seal the fitting against any escape of gas.

When it is desired to introduce an extension pipe into the fitting in order to incorporate an extension line or lines into the existing line with which the terminal extension fitting is connected, it is merely necessary to remove the follower 7d, the gasket 60, and the closure unit 8l and to insert Ithe extension pipe through the follower and the gasket into the body 2li. By reason of the presence of lthe barrier 54, no substantial amount of gas escapes during this operation and it is not necessary to shut down the line or to reduce the gas pressure. As the pipe is inserted into the body 2t) and the sleeve 40, it engages the rib 88 and displaces the barrier 54, as shown in FIG. 4. By reason of the presence of trib 88, pressure is first applied at one point to the barrier 54 and the barrier bends easily as it is gradually disengaged from the sleeve 4G. Suitably, the follower 70 is threaded loosely upon the body 2G before the extension pipe 48 is positioned inwardly sufficiently to engage the rib 88 and then, after the pipe 48 has been shoved further inwardly to displace fully the barrier 54 and, thus provide full fluid communication with the gas interiorly of `body 20, the follower 70 is then quickly tightened upon the body 20 to apply sealing pressure to the gasket 6) which then effectively seals against the surface of the extension pipe 4S to complete the installation.

ln FIGS. 5 to l1 are illustrated diagramimatically typical steps suitably employed in using the terminal extension fitting of this invention to incorporate an extension line as described above. FIG. 5 shows Ithe relationship of parts as the extension pipe 48 is aligned with the fitting l5. A mark 92 is `advantageously made on the pipe to indicate the distance between the outer face of the follower nut 7 0 and the inner end of the enlarged portion of the `body 20 so that, when the mark 92 is just visible fbeyond the follower nut, it will indicate that the pipe extension has been fully in-t serted and that complete communication with the gas in the existing line has been effected. As shown in FIG. 6, the follower nut 7i) and the gasket 6i) are removed from the fitting 1S and mounted upon the end of extension pipe 43 and the closure unit 8l is removed. The extension pipe 48 with the follower nut and gasket are then partially inserted in the fitting, the follower nut lightly tightened upon the body 2f), and the extension pipe is then fully inserted into the fitting up to the mark 92. Upon tightenet ing of the follower nut 70, the installation is completed, as shown in FIG. 7.

In the foregoing description, it will be understood that the extension pipe is adapted to undergo limited axial movement relatively to the fitting 15. If the extension pipe should be so constructed that even this limited relative axial movement is not possible, then the coupling of the extension pipe into the fitting is suitably effected by the system illustrated in FIGS. 8 to 11. In this system, the free end of the extension pipe 48 is cut off to provide a secondary pipe extension element 93, and this secondary element is loosely connected to the remaining portion of the extension pipe 48 by means of a compression coupling Sie such as the well-known Dresser coupling of the type illustrated, for example, in FIG. of Pfefferle et al. U.S. Patent No. 2,021,745, with the centering projection 6016i removed. As will be seen in FIG. 8, the secondary element 93 is fully inserted into coupling 94, with the follower 95' loose, and the follower nut 7@ and gasket et? are then removed and mounted upon the pipe end and the closure unit 81 is then removed. The installation is then completed as previously described in connection with FGS. 5 to 7 with the follower 95 of the coupling 94 being also tightened to complete sealing engagement with Athe secondary pipe extension element 93. Alternatively, as show in FiG. 10, the follower nut 7l) and gasket ofi may be first loosely mounted upon the body 2i) and the secondary element 93 then stabbed into the fitting 1S to the extent indicated by the mark 92, and the follower nut 7d then suitably tightened upon the body 2i). It will be understood that this procedure is also applicable to the systems shown in FlGS. 5 to 7,

it will thus be seen that the only tool needed to effect the rapid and simple interconnection of an extension pipe line with the terminal extension fitting of this invention is a wrench and it will similarly be seen that the connection of the extension line may be effected rapidly with little loss of gas, without requiring the shut-down of the gas line or a reduction in gas pressure, and without requiring the use of skilled labor. Thus, in a gas distribution system as shown diagrammatically in FG. l, wherein a main 9%? has branch outlets 91 leading to existing consumers, when terminal extension fittings of this invention are applied to any terminal ends of the gas net-work as at A and at B, the coupling of a new extension into the existing net-work may be easily and rapidly effected.

It will be understood that various changes and modifications may be made in the embodiments of the invention described above without departing from the scope of the invention as defined in the appended claims. For example, instead of having threads on the follower and on the body of the fitting by means of which these elements art threadly engaged, other means for interconnecting the follower with the body of the fitting to apply sealing pressure to the gasket may be employed. Similarly, the closure unit 81, instead of being hollow as illustrated, may be in the form of a solid plug and may suitably be provided with a recess to receive a Spanner wrench or like tool to facilitate its removal from the body when the connection with the pipe extension is to be made.

A modified form of the terminal extension fitting is shown, for example, in FIG. 2a wherein parts corresponding to those illustrated in FIG. 2 have been given like reference numerals to which 1G() has been added. As shown in this figure, the body 120, instead of having an end 22 for welded connection to the pipe 124, has an end 122 suitably shaped to receive a sealing gasket 1690. which is engaged by a follower cup 176g and a follower 17h11 which threadedly engages the body 129. The pipe receiving aperture of the follower 170:1 has a tapered wall 174g and the gasket has an axial extension 162 which extends into the tapered pipe aperture and is provided with a metallic spring helix or armor 160 of the type shown, for example, in Risley et al. U.S. Patent 2,610,078, which cooperates with the tapered surface of the pipe aperture to prevent axially outward displacement of the pipe 124 from the body 120. The opposite end of the body is generally similar to the corresponding end of body 2Q of FIG. 2, with gasket 160, sleeve 140, barrier 154 and follower 170. The `closure unit 181 is also generally similar to closure member 81 except that it is suitably a single cast member. Centrally, the body 1.2i)` is provided with a radially inwardly-extending annular pipe stop 196 to keep the pipe 124 from extending too far into the body 120.

In some cases, it is desirable to purge a line of air and to equalize the pressure between a pressurized and an unpressurized line. For this purpose, a purging opening 197 is provided and,. until it is ready to be used, it is closed by a plug-v 198. When the extension fitting is placed on the terminal end of a new section of a line it serves as a line cap until another new section is added. The purging construction is provided so that the air in the new section con be vented. Furthermore, when a new line is to be added to an old line provided with a terminal extension fitting as described above, the new pipe is advanced into the fitting only a sufficient amount lto crack the barrier seal, thus allowing the pressure on both sides of the barrier to equalize without producing a sudden shock to the new system in the event Lthe pressures are not already equalized.

It will be understood, therefore, that all matter contained in the foregoing description and in the drawings is to be interpreted as illustrative only and not as limitative lof the invention and it will further be understood that, insofar as they are not mutually incompatible, the variou features and details of construction of the several em-bodiments shown and described are interchangeable with one another.

What we claim and desire to secure by Letters Patent is:

l. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve disposed in said second end of the body portion and a removable barrier carried by said sleeve, said barrier being adapted to be automatically displaced upon introduction of the end of the extension pipe line and having means on its axially-outer side extending axially-outwardly a greater distance than the remainder of said barrier for initial engagement of one circumferential portion only of said barrier by the extension pipe line, whereby to move initially only a portion of said barrier relatively to said sleeve, a removable closure for said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, and means acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

2. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve threadedly engaged in said second end of the body portion and a removable barrier carried by said sleeve, said barrier being adapted to be automatically displaced upon introduction of the end of the extension pipe line and having means on its axially-outer side extending axiallyoutwardly a greater distance than the remainder of said barrier for initial engagement of one circumferential portion only of said barrier by the extension pipe line, whereby to move initially only a portion of said barrier relatively to said sleeve, a removable closure for said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against anat-aser gas leakage, and means acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

3. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve disposed in said second end of the body portion and a removable barrier carried by said sleeve, said barrier being adapted to be automatically displaced upon introduction of the end of the extension pipe line and having a tapered rib on its axially outer side for initial engagement by the extension pipe line, a removable closure for said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, and means acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

4. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve threadedly engaged in said second end of the body portion and a removable barrier of thin sheet metal carried by said sleeve, said barrier being adapted to be automatically displaced upon introduction of the end of the extension pipe line and having a tapered rib on its axially outer side for initial engagement by the extension pipe line, a removable closure for said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, and means acting upon the resilinet sealing means to maintin sealing pressure upon said sealing means.

5. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve threadedly engaged in said second end of the body portion and a removable barrier of thin sheet metal carried by said sleeve, said barrier being adapted to be automatically displaced by bending upon introduction of the end of the extension pipe line and having a tapered rib on its axially outer side for initial engagement by the extension pipe line, a removable closure disposed interiorly of said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, and means acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

6. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end adapted to be connected to the terminal end of the existing pipe line, and a second end, an internal sleeve threadedly engaged in said second end of the body portion and a removable barrier of thin sheet metal carried by said sleeve, said barrier being adapted to be automatically displaced by bending upon introduction of the end of the extension pipe line and having a tapered rib on its axially outer side for initial engagement by the extension pipe line, a removable closure disposed interiorly of said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, said closure having a body portion received by said sleeve and a peripheral flange engageable with said sealing means, and means threadedly engaged with said body portion of said fitting and acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

7. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end of reduced diameter adapted to be connected to the terminal end .of the existing pipe line, and a second end of greater diameter, an internal sleeve having external threads threadedly engaging the wall of said bore in said second end of the body portion, said sleeve having a flange and said bore having a cooperating shoulder for limiting insertion off said sleeve, and a removable barrier of thin sheet metal carried by said sleeve, said barrier comprising a web with a ange engaged with said sleeve and being adapted to be automatically displaced by bending upon introduction of the end of the extension pipe line, a removable closure disposed interiorly of said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, said closure having a body portion received by said sleeve and a peripheral flange engageable with said sealing means, and follower means threadedly engaged with said body portion of said fitting and acting upon the resilient sealing means to maintain sealing pressure upon said sealing means.

8. A terminal extension fitting adapted to be connected to an existing pipe line to permit rapid connection with an extension pipe line, said fitting comprising a body portion having an axial bore, said body portion having a first end of reduced diameter adapted to be connected to the terminal end of the existing pipe line, and a second end of greater diameter, an internal sleeve having external threads threadedly engaging the wall of said bore in said second end of the body portion, said sleeve having a flange and said bore having a cooperating shoulder for limiting insertion of said sleeve, and a removable barrier of thin sheet metal carried by said sleeve, sai-d barrier comprising a web with a fiange engaged with said sleeve and being adapted to be automatically displaced by bending upon introduction of the end of the extension pipe line, a removable closure disposed interiorly of said second end to provide positive sealing of said second end, resilient sealing means acting upon the removable closure and upon the sleeve to seal said closure and said sleeve against gas leakage, said slosure having a body portion received by said sleeve and a peripheral ange engageable with said sealing means, and follower means threadedly engaged with said body portion of said fitting and acting upon the resilient sealing means to maintain sealing pressure upon said sealing means, said follower means being removable during insertion of said extension pipe line into said body portion of said fitting and adapted to apply sealing pressure upon said sealing means to provide fiuidtight engagement with said extension line.

References Cited in the file of this patent UNITED STATES PATENTS 1,933,117 Markle Oct. 3, 1933 FOREIGN PATENTS ,389,553 Germany Feb, 4, 1924 

